Autism spectrum disorders are a group of diseases characterized by varying degrees of impairment in communication skills, social interactions, and restricted, repetitive and stereotyped patterns of behavior. The difference in the diseases depends on the time of onset, the rate of symptom development, the severity of symptoms, and the exact nature of the symptoms. These disorders range from mild to severe impairment and include such diseases as autism, Asperger's syndrome, PDD-NOS, Rett's disorder, childhood disintegrative disorder, semantic communication disorder, non-verbal learning disabilities, high functioning autism, hyperlexia and some aspects of attention deficit hyperactivity disorder. While the exact number of children with autism spectrum disorders is unclear, rates in localized areas of the United States vary from 3.4 children per one thousand to 6.7 children per one thousand. Further, recent studies estimate that 15,000 children aged three through five years, and 78,000 children and young adults aged six through twenty-one years in the United States have autism. Rates in Europe and Asia are similar, with as many as six per one thousand children having at least one autism spectrum disorder. Additionally, there are number of related disorders including anxiety disorders, obsessive-compulsive disorders, social deficit disorders, repetitive disorders and cognitive deficit disorders which exhibit symptoms similar to those displayed in autism spectrum disorders, greatly increasing the size of the affected population.
Characteristics of autism spectrum disorders include social withdrawal and averted gaze including an inability to make eye contact, repetitive behaviors and obsessions, stereotyped movements, anxiety, attention deficit, hyperactivity, depression, a reclusive personality, and the inability to understand feelings. Patients afflicted with autism spectrum disorders may have an aversion to physical affection or contact, ignore communication from others, or if socially engaged, demonstrate a marked inability to communicate or relate to others. Communication difficulties may manifest as a monotone voice, an inability to control the volume of their voice, echolalia or an inability to talk at all. Individuals with autism spectrum disorders may also suffer from visual difficulties, comprehension difficulties, sound and light sensitivity and mental retardation.
Children with autism spectrum disorders do not follow the typical patterns of child development. In some children, hints of future problems may be apparent from birth. In most cases, the problems in communication and social skills become more noticeable as the child lags further behind other children the same age. Some children initially develop normally and then begin to develop differences in the way they react to people and other unusual behaviors. Some parents report the change as being sudden, and that their children start to reject people, act strangely, and lose language and social skills they had previously acquired. In other cases, there is a plateau in development that becomes increasingly noticeable.
The underlying causes of autism spectrum and related disorders are unclear. Postmortem and MRI studies have implicated anomalies in many major brain structures including the cerebellum, cerebral cortex, limbic system, corpus callosum, basal ganglia, and brain stem. Other research is examining the role of neurotransmitters such as serotonin, dopamine, and epinephrine.
Currently, autism spectrum disorders are treated using applied behavior analysis or other behavior modification techniques; dietary modification such as a gluten or casein free diet, or large doses of vitamin B6 in combination with magnesium. Medications prescribed for autism address specific symptoms such as anxiety and depression and include agents such as fluoxetine, fluvoxamine, sertraline and clomipramine. Antipsychotic medications such as chlorpromazine, thioridazine, and haloperidol have been used to treat behavioral problems. Anticonvulsants such as arbamazepine, lamotrigine, topiramate, and valproic acid have been given to prevent seizures.
Results of a study (Hollander et al., American College of Neuropsychopharmacology Annual Meeting, December 2006) were reported to show that autistic adults who were given an intravenous doses of oxytocin had a statistically significant reduction in repetitive behaviors that are associated with autism.
Unfortunately, current treatments for autism spectrum and related disorders are mainly symptomatic and have proven unsuccessful in allowing such children and adults to become symptom, or disorder, free. There is therefore an unmet need in the art for alternative treatments for autism spectrum disorders and related pathologies.